1 . Field of the Invention
The present invention relates to an apparatus for driving a plasma display panel, and more particularly, to an apparatus for driving a plasma display panel including a scan driver.
2 . Description of the Background Art
FIG. 1 is a block diagram of a plasma display panel driver according to a related art. Referring to FIG. 1, a signal processing unit 110 converts a video signal inputted form outside to video data suitable for a drive of a plasma display panel.
A data sort unit 120 reconfigures the video data of 1-TV field into a plurality of subfields for a gray scale processing of the video data converted by the signal processing unit 110.
An X-electrode drive unit 130 and a Y-electrode drive unit 140 apply an address pulse and a scan pulse for forming a wall voltage in a discharge cell of the plasma display panel to an X-electrode and a Y-electrode, respectively. And, the Y electrode drive unit 140 and a Z-electrode drive unit 150 alternately apply sustain pulses for sustaining a discharge of the discharge cell having the wall charge formed thereon to the Y-electrode and a Z-electrode, respectively.
A main control unit 160 controls video data re-sorted by the data sort unit 120 according to an external video signal so that the re-sorted video data is sequentially read to be supplied to the X-electrode drive unit 130 by 1-scan line quantity. And, the main control unit 160 applies a logic control pulse to a high voltage drive circuit unit 170.
The high voltage drive circuit unit 170 receives the logic control pulse from the main control unit 160 and then applies a high voltage control pulse to the X-, Y-, and Z-electrode drive units 130 140, and 150.
In this case, the Y-electrode drive unit 140 includes a scan driver 210, as shown in FIG. 2, to apply a scan or sustain pulse to the Y-electrode. The related art scan driver 210 is an integrated circuit (IC) package including a pair of switching devices. A pair of the switching devices, which form one channel to apply the scan or sustain pulse to the Y-electrode, need to employ switching devices having high strength. As the related art scan driver 210 consists of a pair of the high-strength switching devices, costs are raised and a volume of the IC package increases.
Moreover, for a channel that is not selected by the scan driver 210 in a scan process, first switching devices 211-1 to 211-n are always turned on to hold a ground level. Hence, power consumption increases to cause more damage to the IC package.
For instance, if a cannel corresponding to a first Y-electrode Y1 is selected in the scan process, the rest of Y-channels Y2 to Yn are not selected. Once the corresponding channel is selected, a second switching device 213-1 of a first scan driver 210-1 corresponding to the selected channel is turned on as well as a scan switching device 220. Simultaneously, first switching devices 211-2 to 211-n of scan drivers 210-2 to 210-n corresponding to the unselected channels and a ground switching device 230 are turned on.
Once the switching devices are driven and once a data pulse is applied to the X-electrodes (X1 to Xm), a write operation is performed on a cell situated on a first line. Moreover, the data pulse is grounded via the first switching devices 211-2 to 211-n of the scan drivers 210-2 to 210-n corresponding to the rest of the Y-electrodes Y2 to Yn and the ground switching device 230.
However, in doing so, since the unselected channels (n-1) outnumber the selected channel (1), the power consumption caused by the grounding is raised. And, it is also highly probable that power fluctuation within the IC package may break down the devices.
A reference number ‘240’ in FIG. 2 is a switching device to apply a sustain voltage (+Vsy) to the Y-electrode, and a reference number ‘250’ in FIG. 2 is a switching device to apply a sustain voltage (+Vsz) to the Z-electrode.